Electric circuit interrupter



Feb. 21, 1939. D. s. llvERs ELECTRIC CIRCUIT INTERHUPTER Filed Sept. 1, 1937 QUV/ WM w 3% V0. f M

g 10 to the re-set. but also to Patented F's-2 193a um-res STATES PATENT amass oFi-" ca' j morale omon rr m'r'nnnurma Durward s. Rivers, Indianapolis, Ind. Application September 1,4937, Serial No. 181,?95

d Claims. 200-116) This invention relates to a plug type electrical circuit protector designed to replace the ordinary fuse embodying fusible metal. g The primary object of the invention is to provide a simplified structure which may be reset following circuit in tions on overloads.

A further important object of the invention is to providenot only an extremely reliable op-' eration in that part of the structure pertaining provide an additional safety device in the form of a fuse link in series with the re-set Further important objects, advantages and features of the inlventionwill be found in the unique combination of the elements as indicated in the appended claims, and as will become more apparent in the following description of one particular form of the invention as illustrated inv the accompanying drawing, in which:- 20 Fig. 1 is a diametrical verticalsection through the structure embodying the invention;

Fig. 2, a horizontal transverse section on the.

line 2-2 in Fig. 1; and

Fig. 3, a horizontal transverse section on the 25 line 3-3-in Fig. 1.

in the various views of the drawing.

A body III is formed of a suitable insulating material to have an outer cylindrical surface and an internal cavity. This cavity II, in the form herein shownfis circular in cross section. An axial terminal I 2 extends through the floor or inner end of the body l0 and through the foot I! of the bi-metal strip I to secure the foot I3 firmly against the inner side of the floor by turning the head of the terminal l2 in the form of a rivet. The floor of the body I0 is preferably recessed in order to provide for a seat for the foot of the bi-metal I4 and also an externally extending boss IS on the end of the body l0 so as to present the outer end of the terminal l2 at a distance from the body |0.. While the member H has been referred to as being made of the bi-metal, it is sufllcient that this member be of any thermo-responsive material which will per-' mit suiiicient distortion of the metal to interrupt the ci cuit as will hereinafter more fully be descrit 2d. A sleeve .or ferrule I6 surrounds the body Ill and has an inturned .flange l1 to abut the end of the body I surrounding the protruding boss IS. The other end of the ferrule i6 is engaged with the body ll by forming detents i8 fitting into indentations ll around the body. four of 55 such indentations being herein shown, Fig. 3.

inserted pin.- "I'he'spring 22 .a looped portion 2|, yieldingly of the metal 2|. 'Like characters of reference indicate like parts It isunderstood that this engagement of the body with the ferrule is made-at the upper end of the ferrule as indicated by. sections shown in Fig. 3. v The body I0 is provided with a side window 2|. .5 A length of metal 2| of suitable cross sectional area and composition, to melt at a. predetermined overload is formedto have a U-shape, whereby the metal 2| may be entered through the window and pushed upwardly toengage the'body ll 10 between the legs of the metal, as indicated in Fig. 1. In this position of the outer'leg of the metal 2| is in electrical contact with the ferrule i6 and the inner leg of the metal extends along the inside of the cavity'against the body ll.

Across the upper er l of the body II is posi tioned a suitable support, 22, herein shown as,an is formed to have the major portion of the circumference of this 20 From the portion 24 is carried a foot 25 downwardly into the cavity il a sufficient length as will permit the foot 25 to bear against and over an appreciable area of the inner leg From the other side of the por- 25 tion 2|, the spring 22 extends across the cavity H normally in aposition inclined upwardly, as indicated by dash lines in Fig. 1. The outer terminal end of the spring 23 is preferably provided with a round end, herein shown as formed by simply turning over the end of the spring.

The thermostatic metal is carried upwardly through the cavity II to a position as indicated in Fig. 1, whereby the spring 22, when pushed downwardly, may engage by its free end under the hook 26, formed in the upper end of the metal H, so that the normal position of the spring 23 is that when it is so engaged and as' indicated by the solid lines in Fig. 1.

An indicating and reset button 21 is provided 40 with a body herein shown as circular in cross section and is further provided with a tongue 28, having a slot therethrough, through which the spring 23 is carried. The cap 29 is provided to have a bore therethrough slidingly receiving the body of the button 21 so'that when the cap 28 is attached to the body l0, the button 21 will be pushed outwardly to some such position as indicated by the dash lines in Fig. 1, when the spring 22 is released from the engagement with the metal H, and further, the cap 22 will guide the button 21 when the button is pushed inwardly to carry the spring 23 back into engagement with the metal I. This cap 2!, as is also the button 21, ts preferably made of some suitable shown) and will provide an. electrical circuit from the. terminal I2 through the metal It, spring 23, fuse link 2i, and the ferrule or sleeve Id The metal id is so selected and sized that when a predetermined overload arises in the circuit, the metal It will bend outwardly from the axis of the body a sumcient distance to release the spring 23, whereupon the circuit is broken. When the overload condition is removed, and the bi-metal i i has cooled sumciently, this 'bi-metal will have returned to the normal position to again receive and engage with the spring 23 to re-establish the circuit. However, should forany reason the members it and 23 refuse to separate on an overload, the metal id, being formed to carry a slightly greater overload, will then melt and break the circuit. This fuse link 2B is provided to break the circuit only on failure of the members Hi and 23 to separate.

However, in the arrangement herein shown, it

would be an extremely rare occasion when the fuse link it would be called upon to break the circuit.

le 1 have herein shown and described my invention in theone form. as is best known to me, it is obvious that structural changes may be made without departing from the spirit of the invention and I therefore do not desire to be limited to this precise form beyond the limitations as may be imposed by the following claims.

I claim:

1. In a plug type circuit interrupter, a body of said spring foot with said sleeve, a cap over said body, and a reset button slidingly guided through said cap to have an end in the path of said spring, said button having a slot therethrough through which said spring passes.

2. In a plug type circuit interrupter, a body of insulation having a cavity, an axial terminal passing through the body into the cavity, a sleeve terminal surrounding the body, a thermostatically shiftable metal strip anchoredby one end anemia in said cavity and electrically connected with said axial terminal, a spring, a supporting'member carried by said body over which said spring wraps, one end of the spring being carried down into said cavityand yieldingly toward a wall thereof, the other end of the spring being yieldingly carried transversely over said cavity into releasable engagement with an outer portion of said metal strip, means electrically connecting saidspring foot with said sleeve, a cap over said body, and a reset button slidingly guided through said cap to have an end in the path of said spring, said sleeve and, spring connecting means consisting of a U-shaped metal piece entered through a window in said body and straddling the body wall to have one leg abutted by said spring foot and its other leg connected with said sleeve.

3. In a plug type circuit interrupter, a body of insulation having a cavity, an axial terminal passing through the body into the cavity. a sleeve terminal surrounding the body, a thermiostati= cally shiftable metal strip anchored by one end in said cavity and electricallyconnected with said axial terminal, a spring, a supporting mereber carried by said body over which said spring wraps, one end of the spring being carried down into said cavity and yieldingly toward a wall thereof, the other end of the spring being yieldingly carried transversely over said cavity into releasable engagement with an outer portion of passing through the body into the cavity asleeve terminal surrounding the body, a ther mostatlcally shiftable metal strip anchored by one end in said cavityand electrically connected with said axial terminal, a spring, a supporting member carried by said body over which said spring wraps, one end of the spring being carried down into said cavity and yieldingly toward a wall thereof, the other end of the spring being yieldingly carried transversely over said cavity into releasable engagement with an outer portion of said metal strip, means electrically connecting said spring foot with said sleeve, a cap'over said body, and a reset button slidingly guided through said cap to have an end in'the path of said spring, said button end having a slot therethrough through which said spring passes, said button end also having a' shoulder thereon above said slot limiting outward travel of the button and said spring.

, DURWARD S. RIVERS. 

